Can You Find the Error?

I used to be the editor of the “Media Clips” column in the Mathematics Teacher journal. One objective of the column was to identify the use of incorrect mathematics in print. The following flyer from H. H. Gregg would have been a great example.

My favorite entry in the “Media Clips” column was a clip from the Salt Lake Tribune on October 11, 2002, which read:

A Salt Lake County Health Department inspector paid a visit recently [to the Coffee Garden restaurant] and pointed out that research by the Food and Drug Administration indicates that one in four eggs carries salmonella bacterium, so restaurants should never use more than three eggs when preparing quiche. [The Coffee Garden’s quiche recipe calls for four fresh eggs.]

Priceless.

Anyway, back to H. H. Gregg. The image above may be too small or blurry to identify the error, so here’s an enlargement.

I gave the flyer to my sons and told them that they could have ice cream for dessert if they were able to identify the math error. I’ll make the same offer to you — first person to post the error to the comments gets an ice cream cone from me.